Update docstrings of CoulombTwoBody.jl and HydrogenAtom.jl

src/CoulombTwoBody.jl

@@ -107,7 +107,7 @@ end
   &= - \frac{Z}{r/a_0} E_\mathrm{h},
 \end{aligned}
 ```
-The domain is $0\leq r \lt \infty$.
+where ``E_\mathrm{h} = \frac{\hbar^2}{m_\mathrm{e}{a_0}^2} = \frac{e^2}{4\pi\varepsilon_0a_0} = \frac{m_\mathrm{e}e^4}{\left(4\pi\varepsilon_0\right)^2\hbar^2}`` is the Hartree energy, one of atomic unit. The domain is $0\leq r \lt \infty$.
 """ V(model::CoulombTwoBody, r)
 
 @doc raw"""
@@ -117,7 +117,7 @@ The domain is $0\leq r \lt \infty$.
 E_n
 = -\frac{(z_1 z_2)^2}{2n^2} \frac{\mu}{m_\mathrm{e}} E_\mathrm{h},
 ```
-where $\mu=\left(\frac{1}{m_1}+\frac{1}{m_2}\right)^{-1}$ is the reduced mass of particle 1 and particle 2, ``E_\mathrm{h}`` is the Hartree energy, one of atomic unit. About atomic units, see section 3.9.2 of the [IUPAC GreenBook](https://iupac.org/what-we-do/books/greenbook/). In other units, ``E_\mathrm{h} = 27.211~386~245~988(53)~\mathrm{eV}`` from [here](https://physics.nist.gov/cgi-bin/cuu/Value?hrev).
+where $\mu=\left(\frac{1}{m_1}+\frac{1}{m_2}\right)^{-1}$ is the reduced mass of particle 1 and particle 2, ``E_\mathrm{h} = \frac{\hbar^2}{m_\mathrm{e}{a_0}^2} = \frac{e^2}{4\pi\varepsilon_0a_0} = \frac{m_\mathrm{e}e^4}{\left(4\pi\varepsilon_0\right)^2\hbar^2}`` is the Hartree energy, one of atomic unit. About atomic units, see section 3.9.2 of the [IUPAC GreenBook](https://iupac.org/what-we-do/books/greenbook/). In other units, ``E_\mathrm{h} = 27.211~386~245~988(53)~\mathrm{eV}`` from [here](https://physics.nist.gov/cgi-bin/cuu/Value?hrev).
 """ E(model::CoulombTwoBody; n=1)
 
 @doc raw"""

src/HydrogenAtom.jl

@@ -85,7 +85,7 @@ end
   &= - \frac{Z}{r/a_0} E_\mathrm{h},
 \end{aligned}
 ```
-The domain is $0\leq r \lt \infty$.
+where ``E_\mathrm{h} = \frac{\hbar^2}{m_\mathrm{e}{a_0}^2} = \frac{e^2}{4\pi\varepsilon_0a_0} = \frac{m_\mathrm{e}e^4}{\left(4\pi\varepsilon_0\right)^2\hbar^2}`` is the Hartree energy, one of atomic unit. The domain is $0\leq r \lt \infty$.
 """ V(model::HydrogenAtom, r)
 
 @doc raw"""
@@ -96,7 +96,7 @@ E_n
 = -\frac{m_\mathrm{e} e^4 Z^2}{2n^2(4\pi\varepsilon_0)^2\hbar^2}
 = -\frac{Z^2}{2n^2} E_\mathrm{h},
 ```
-where ``E_\mathrm{h}`` is the Hartree energy, one of atomic unit. About atomic units, see section 3.9.2 of the [IUPAC GreenBook](https://iupac.org/what-we-do/books/greenbook/). In other units, ``E_\mathrm{h} = 27.211~386~245~988(53)~\mathrm{eV}`` from [here](https://physics.nist.gov/cgi-bin/cuu/Value?hrev).
+where ``E_\mathrm{h} = \frac{\hbar^2}{m_\mathrm{e}{a_0}^2} = \frac{e^2}{4\pi\varepsilon_0a_0} = \frac{m_\mathrm{e}e^4}{\left(4\pi\varepsilon_0\right)^2\hbar^2}`` is the Hartree energy, one of atomic unit. About atomic units, see section 3.9.2 of the [IUPAC GreenBook](https://iupac.org/what-we-do/books/greenbook/). In other units, ``E_\mathrm{h} = 27.211~386~245~988(53)~\mathrm{eV}`` from [here](https://physics.nist.gov/cgi-bin/cuu/Value?hrev).
 """ E(model::HydrogenAtom; n=1)
 
 @doc raw"""